Any advance on the peanuts paid to authors now?

Sometime in the next few days I will be writing one of the most beautiful four-letter words in the English language: ends.

I am polishing off my new book, about gambling in early Victorian England and the plot to steal the Derby of 1844.

As you can imagine, Dan Brown must be terrified.

With impeccable timing, I will deliver my manuscript to my publisher Alan Samson at Weidenfeld & Nicolson at a moment when the writing of moderately serious non-fiction history books, such as the ones I attempt, appears to be in peril.

A quick scan of the best-seller lists would lead me to believe that the perfect book of 2009 would be written by Jordan about Michael Jackson's part in the D-Day landings - hot areas that my book heroically fails to address.

Of course one of the great things about finishing a book is the opportunity to collect the delivery portion of the advance.

However, at this stage I think it only fair to warn Jack Barclay that I will not be popping in for a new Bentley just yet.

What with coming up with the idea, writing a proposal, the endless researching and interminable reading, I think it has taken me about three or four years to write this book. Of course I have been doing other things as well. In fact, I have to.

The mathematics are alarming. Based on an hourly rate, I would guess that I am working perilously close to the minimum wage.

If I divide the advance by the number of words that I have written I arrive at a rate that is humiliatingly low. And I am scared to tot up all the invoices from my brilliant research assistant, as I fear that I might turn out to be working for her.

What is aggravating is that the better my books get, the less I seem to be paid for them. Of course I have to see what Alan thinks of my latest offering but writing is a craft.

Much like making a piece of furniture, laying a carpet or fixing a leaking pipe, the more practice you put in the better you get but I have yet to find a plumber who would work for an author's rates.

The first serious book I wrote (not counting a restaurant guide and contributions to fashion books) was about a bisexual gambling dandy and political fixer called Count d'Orsay.

That deal was signed in the palmy days of the late 20th century when history was the new gardening or some such, and for this auspicious debut I got paid considerably more than I will get for my book about the Derby of 1844.

I think it is a simple matter that people are more interested in the memoirs of living celebrities rather than dead men who wore top hats and frock coats - and I have only myself to blame if I persist in writing about the era of the Reform Bill and the repeal of the Corn Laws.

It is particularly galling that the amount of work that goes into creating such a book is substantial and that when it is finished the reservoir of knowledge will remain untapped.

I suppose that is why increasingly historians are putting their knowledge to sound commercial use and writing historical novels based on their period of expertise.

Simon Sebag Montefiore has mined his unique knowledge of Russian history for the novel Sashenka, while Saul David, chronicler of Imperial Britain's military engagements in the 19th century, has brought out a work of fiction set in the Zulu War of 1879.

The big-selling histories tend to be on subjects with which that portion of the public that still buys books is already familiar, which leaves a gap, more of a chasm really, as Andrew Roberts puts it "from Henry to Hitler".

And as my publisher explained to me, "where there are gaps to be plugged people prefer to read it as fiction: with the possible exception of Simon Schama's The Embarrassment of Riches; they are not going to buy a non-fiction book on 17th-century Holland, they are going buy The Girl with the Pearl Earring".

The Booker shortlist this year, which is dominated by historical novels, bears him out.

Still, it could be worse for non-fiction. There are bright spots, the premier league of serious history writing is performing briskly.

The big hit of the summer was Antony Beevor's D-Day and Andrew Roberts's new book The Storm of War is well storming up the best-seller lists.

He has a theory that there is a strong constituency of autodidacts, who were taught history poorly at school and wish to better instruct themselves by reading big books about big subjects, in short, the sort of thing that he writes and I well don't: one of my more recent books, Dancing Into Battle, dealt with the social scene in Brussels at the time of Waterloo.

And as in football so in publishing, there is a gap between the premier league and the lower divisions.

As Roberts says: "I have heard that people have been getting advances that barely cover the taxi fare home, and these are quite well known people on subjects that should be quite saleable."

I am as greedy as the next man and I would like to be paid like Harold Robbins or Somerset Maugham (about whom Selina Hastings has written a biography I am looking forward to immensely).

But I cannot hold my publisher responsible for the fact that my books are not skipping off the shelves like the Twilight series, and that Harvey Weinstein has not optioned my entire back catalogue (including the book I wrote about the trenchcoat) for movies starring Nicole Kidman and Daniel Day-Lewis (although the latter would be perfect in the lead role in a film of my Derby book).

I suppose that it is in part vanity that drives me on; that, and a hunger for knowledge. As such I am grateful that I get paid for my books at all.

Moreover, writing these things appeals to the gambler in me. Rather like betting on the spin of a wheel at roulette, you just never know the alignment of public taste, heavenly bodies and Hollywood studios next spring might favour a book about gambling and skulduggery on the Victorian turf.

I hope that you will like it and that you will buy it, although I was told by my publisher that the sort of article that I am writing now is really too far in advance of publication to have any impact on sales, so the best that I can hope for is that you will cut this page out of the Evening Standard and keep it on the front of the fridge until such time as my book makes it into print.